Method and device for transmitting burst signal in mobile communication system, information distribution method, and information distribution controller

ABSTRACT

In a method and an apparatus of transmitting a burst signal when the burst signal is transmitted from a transmitting station to a receiving station at a transmission power value and/or a transmission rate determined in accordance with a state of a radio channel between the transmitting and receiving station in a mobile communication system, based on a comparison result between a criterion predetermined according to a state of the radio channel and/or a transmission waiting state of the signal, whether or not the burst signal is to be transmitted is determined, and, when it is determined that the burst signal is to be transmitted, the burst signal is transmitted from the transmitting station to the receiving station.

TECHNICAL FIELD

The present invention relates to a method of transmitting a burst signalin a mobile communication system, and an apparatus therefor, and, indetail, to a method of transmitting a burst signal in a case where theburst signal is transmitted from a transmitting station to a receivingstation at a transmission power value and/or transmission rate valuedetermined in accordance with a state of a channel between thetransmitting station and receiving station in a mobile communicationsystem, and a transmission device which transmits the burst signal tothe receiving station at such a transmission power value and/ortransmission rate value. Further, the present invention relates to ainformation distributing method to which the above-mentioned method ofand apparatus for transmitting the burst signal can be applied.

BACKGROUND ART

In a mobile communication system, when a burst signal istransmitted/received between many base stations disposed in a servicearea and a mobile station, a position and a radio transmission/receptionstate of which change every moment, it is an important problem how anappropriate base station is selected, how an appropriate transmissionpower is to be determined, how a transmission rate in adaptivemodulation is determined, and how transmission of the burst signal(data) is performed at an appropriate time, for reducing a peaktransmission power and increasing a system capacity. Especially, in amultimedia communication for which data amount, required performance andquality vary variously, it has become an important problem todistribute, in response to a transmission request, a necessary andsufficient resource (power resource, frequency resource, and so forth)to each communication, and, thereby, to achieve guarantee of service andincrease in user capacity.

Transmission of the burst signal in a conventional mobile communicationsystem is performed as follows: That is, burst signals provided to atransmitting station (for example, a base station) are stored in awaiting row, one by one, the burst signals in this waiting row are takenwithout delay, and a thus-taken burst signal is transmitted to areceiving station (for example, a mobile station) at an immediatefollowing transmission occasion (timing of a slot, or the like).Thereby, the burst signals provided to the transmitting station one byone are transmitted to the receiving station in a manner such that thedelay becomes minimum.

Further, according to the conventional mobile communication system, atransmission power value and/or a transmission rate value are determinedin accordance with a state of a channel between a transmitting stationand a receiving station. That is, the channel state between thetransmitting station and receiving station (for example, a signalattenuation factor depending on a distance between the transmittingstation and receiving station, or the like) is measured, and, based onthe measured value, the transmission power value and/or transmissionrate value are determined in a manner such that the receiving stationcan receive the signal at a predetermined reception quality (forexample, a reception level). As a result of the transmission power valueand/or transmission rate value of the burst signal to be transmittedfrom the transmitting station to the receiving station being thusdetermined, the receiving station can always receive the burst signalwith the predetermined reception quality even when the mutual positionalrelationship between the transmitting station and receiving station, theattenuation characteristic of transmission wave, and so forth varyvariously due to a movement of the mobile station, change in theselected base station, and so forth.

In the mobile communication system in which the burst signal is thustransmitted from the transmitting station to the receiving station atthe transmission power value and/or transmission rate value determinedin accordance with the state of the radio channel between thetransmitting station and receiving station, in a conventional method oftransmitting the burst signal in which a transmitting time is determinedin a manner such that delay of the burst signal provided to thetransmitting station is minimum, there is a case where, at the time atwhich the transmission should be performed, the state of the channel isnot satisfactory (for example, the fading comes to be degraded too much,or the like), the transmission power value determined in accordance withthis state becomes too large. In such a case, if the burst signal istransmitted at the thus-determined transmission power value, the peaktransmission power becomes larger, and, thereby, the power consumptionin the transmitting station increases. Further, due to increase of theaverage transmission power value caused by the increase of the peaktransmission power value, the interference to communication of othermobile stations becomes larger.

Thus, in the conventional method of transmitting the burst signal, atime at which the burst signal is to be transmitted is determined merelyin a manner such that the delay becomes minimum, without considerationof the state of radio channel between the transmitting station andreceiving station. Thereby, the transmission power value and/ortransmission rate value determined in accordance with the state of radiochannel do not necessarily become appropriate ones when the burst signalis transmitted.

Further, in such a mobile communication system, distribution ofinformation to a mobile set is performed as follows:

Periodically, path losses (or an average thereof) of channels between amobile set and a plurality of base stations are measured, and one basestation having the minimum measured value is selected. Then, data isdistributed to the mobile set from the thus-selected base stationwirelessly.

The period of selecting the above-mentioned base station can be set to arelatively long one (for example, several seconds), or can be set to arelatively short one (for example, several milliseconds). When thisperiod is set to a relatively long one, data is distributed to themobile set substantially from the base station which is nearest from thecurrent position of the mobile set. Thereby, it is possible to performdata distribution with an averagely stable condition. When theabove-mentioned period is set to a relatively short one, one basestation which has the minimum instantaneous path loss is selected one byone every minute time interval. Thereby, in a mobile communicationsystem in which transmission power control is performed in a manner suchthat the reception level at a mobile set is approximately fixed, it ispossible to reduce the average transmission power.

When the period of selecting the base station by which transmission isperformed to the mobile set is thus relatively long, information isdistributed to the mobile set from the single base station for arelatively long time interval. Accordingly, the information distributingwhich is performed from the single base station to the mobile set for arelatively long time interval is likely to be affected by a randomlyoccurring instantaneous variation in fading. For example, when the pathloss in the radio channel between the mobile set and the relevant basestation instantaneously increases (instantaneous increase of fading),the error rate of received information in the mobile set may increase,or instantaneously the transmission power may increase so as tocompensate for this path loss.

Thus, when the period of selecting the base station by whichtransmission is performed to the mobile set is relatively long,reception of information at the mobile set is performed not necessarilyin a satisfactory condition.

Further, when the period of selecting the base station which shouldperform transmission to the mobile set is relatively short as mentionedabove, it is necessary to perform processing such as measurement of pathloss, selection of the base station based on the measured value within arelatively short period, and so forth. Accordingly, the control amountrequired for the information distribution increases.

Therefore, an object of the present invention is to provide a method ofand a device for transmitting a burst signal by which a transmissiontime of the burst signal can be determined such that, when the burstsignal is transmitted, the transmission power value and/or transmissionrate value determined in accordance with a state of the radio channelbecomes not an inappropriate one for the mobile communication system aspossible.

Further, the present invention has an object to provide an informationdistributing method for a mobile communication system by which, whilethe control amount required for information distribution can be reducedas possible, reception of information by a mobile set can be performedat a state which is as good as possible, and also, an informationdistribution control device by which, while the control amount requiredfor information distribution can be reduced as possible, reception ofinformation by a mobile set can be performed at a state which is as goodas possible.

DISCLOSURE OF THE INVENTION

The above-mentioned problems can be solved by the following presentinvention:

(1) In a method of transmitting a burst signal when the burst signal istransmitted from a transmitting station to a receiving station at atransmission power value and/or transmission rate determined inaccordance with a state of a radio channel between the transmittingstation and receiving station in a mobile communication system, aconfiguration is made such that it is determined as to whether or notthe burst signal is to be transmitted based on a comparison resultbetween a criterion previously determined in accordance with the stateof the radio channel and/or a transmission waiting state of the signaland the state of the radio channel between the transmitting station andreceiving station; and the burst signal is transmitted from thetransmitting station to the receiving station when it has beendetermined that the burst signal is to be transmitted.

In this method of transmitting a burst signal, when it is determinedthat the burst signal is to be transmitted based on a comparison resultbetween a criterion previously determined in accordance with the stateof the radio channel and/or a transmission waiting state of the signaland the state of the radio channel between the transmitting station andreceiving station, the burst signal is transmitted from the transmittingstation to the receiving station at the transmission power valuedetermined in accordance with the state of the radio channel.

According to this method of transmitting a burst signal, the comparisonresult between the above-mentioned criterion and the state of the radiochannel reflects the state of the radio channel. Thereby, a time oftransmission of the burst signal (whether or not the burst signal is tobe transmitted) is determined in consideration of the state of the radiochannel.

The above-mentioned transmitting station may be either one of a basestation and a mobile station of the mobile communication system. Whenthe base station is the transmitting station, the mobile station is thereceiving station. When the mobile station is the transmitting station,the base station is the receiving station.

The above-mentioned criterion is determined such that the transmissionpower value and/or transmission rate determined based on the state ofthe radio channel at the time of transmitting the burst signaldetermined based on the comparison result between the criterion and thestate of the radio channel is not inappropriate for the mobilecommunication system as possible. Further, this criterion may be madevariable adaptively for each time zone, each mobile station performingcommunication, or each base station performing communication.

(2) In a standpoint that the state of the radio channel can be directlydetermined, in the above-mentioned method of transmitting of a burstsignal, the above-mentioned criterion may be determined based on thstate of the radio channel.

The state of the radio channel which is used as a base for determiningthe above-mentioned criterion represents the transmission state of theburst signal directly or indirectly, and, for example, may be expressedby any of instantaneous path loss variation value between thetransmitting and receiving stations, data transmission error rate,transmission throughput, distance between the transmitting and receivingstations, relative positional relationship between the transmitting andreceiving stations, interference power value which the receiving stationreceives from another transmitting station, number of receiving stationson the other ends to which the burst signal is transmitted through asame antenna, desired time of transmission, transmission data amount,and/or the like, short-span average thereof, long-span average thereof,reception-end transmission permission/non-permission determinationdetermined on the receiving device, or a combination of some thereof.These can be obtained by direct measurement in the transmitting device,or may be obtained as a result of one measured in the reception devicebeing transmitted as a control signal. When the measurement is made inthe receiving device, the measured value may be transmitted to thetransmitting device in a form of a real number or the like as it is as acontrol signal, or determination may be made therefor based on acriterion provided in the receiving end, and one expressed by anumerical value in binary or more finite levels may be transmitted tothe transmitting device as a reception-end transmissionpermission/non-permission determination.

(3) In a case where it is determined as to whether or not the burstsignal is to be transmitted in consideration of the state of the radiochannel, and, based on the determination result, the burst signal istransmitted, a waiting time for the burst signal is long when an amountof the burst signal provided to the transmitting station as the burstsignals to be transmitted is large. Such a situation is not anappropriate state for the mobile communication system. Therefore, in astandpoint of avoiding such a situation, the determination as to whetheror not the burst signal is to be transmitted may be performed furtherdepending on the transmission waiting state of the burst signal,according to the present invention.

In this method of transmitting a burst signal, as the determination asto whether or not the burst signal is to be transmitted is madedepending on the waiting state of the burst signal, it is possible totransmit the burst signal provided to the transmitting station withoutdelay as possible while maintaining the transmission power value and/ortransmission rate as an appropriate state as possible.

The above-mentioned waiting time for the burst signal represents awaiting state until the burst signal provided to the transmittingstation is transmitted, directly or indirectly, and, for example, may beexpressed by any of or a combination of some of a data amount of theburst signal in the waiting state, the maximum delay time of the burstsignal in the waiting state, the average delay time of the burst signalin the waiting state and an immediately preceding transmissionsituation.

(4) As the above-mentioned determination as to whether or not the burstsignal is to be transmitted is made based on the comparison resultbetween the above-mentioned criterion and the state of the radiochannel, the above-mentioned waiting state of the burst signal may bereflected by either the above-mentioned criterion or the state of theradio channel. In a standpoint that the waiting state of the burstsignal can be easily reflected by the determination as to whether or notthe burst signal is to be transmitted, the above-mentioned criterion maybe determined depending on the transmission waiting state of the burstsignal, in the method of transmitting of a burst signal, according tothe present invention.

(5) When data is transmitted as the burst signal, various performancesare required for transmission of the burst signal. In a standpoint thatsuch requirements can be properly dealt with, according to the presentinvention, the determination as to whether or not the burst signal is tobe transmitted may be performed further depending on performancesrequired for transmitting the burst signal, in the method oftransmitting of a burst signal.

As the determination as to whether or not the burst signal is to betransmitted is thus performed further depending on performances requiredfor transmitting the burst signal, it is possible to transmit the burstsignal in a manner such as to satisfy the required performances, whilemaintaining the transmission power value and/or transmission rate as anappropriate state as possible. For example, for the burst signal of datafor which relatively fast transmitting rate is required, even when theradio transmission state is somewhat unsatisfactory, the burst signalmay be transmitted by the burst signal at the transmission powervalue/transmission rate in accordance with this state.

The performances required for transmitting the burst signal representsperformances required when the burst signal is transmitted, and, forexample, may be expressed by any of or a combination of some of requiredtransmission rate, required transmission priority level, required errorrate, required maximum delay amount, and required average delay amount.

(6) As the above-mentioned determination as to whether or not the burstsignal is to be transmitted is made based on the comparison resultbetween the above-mentioned criterion and the state of the radiochannel, the above-mentioned performances required for transmitting theburst signal may be reflected by either the above-mentioned criterion orthe state of the radio channel. In a standpoint that the performancesrequired for transmitting the burst signal can be easily reflected bythe determination as to whether or not the burst signal is to betransmitted, the above-mentioned criterion may be determined dependingon the performances required for transmitting the burst signal, in themethod of transmitting of a burst signal, according to the presentinvention.

(7) Further, in a standpoint that the power resource can be distributedin accordance with the performances required for transmitting the burstsignal, at least one of the transmission power value and transmissionrate may be determined further depending on the performances requiredfor transmitting the burst signal.

(8) In comparison between the above-mentioned criterion and the state ofthe radio channel, originally, the transmission power value and/ortransmission rate is determined based on the state of the radio channel.Accordingly, in a standpoint that processing can be performed easily, aconfiguration may be made such that the criterion is expressed as areference transmission power value and/or reference transmission rate,and, it is determined as to whether or not the burst signal is to betransmitted based on the comparison result between the referencetransmission power value and/or reference transmission rate andtransmission power value and/or transmission rate determined inaccordance with the state of the radio channel, according to the presentinvention.

(9) In cellular mobile communication, in order to reduce interferencepower to other cells, it is needed to provide an upper limit to thetotal of transmission powers from one base station. In this case, it isneeded to consider states of a plurality of radio channels (for example,a total transmission power value). In this standpoint, theabove-mentioned state of the radio channel may include not only thestate of the radio channel between the transmitting station andreceiving station to which the burst signal is addressed but also thestate of a radio channel with another receiving station.

For example, the above-mentioned criterion is a reference total powervalue, and bursts which can be transmitted are selected from a pluralityof burst signals such that the total of transmission power values of theplurality of burst signals do not exceed the above-mentioned referencetotal power value. In this selection, for example, burst signals areselected from the plurality of burst signals in a predetermined order,the total of transmission power values thereof is obtained, and,determination is made such that, when this total does not exceed theabove-mentioned reference total power value, the thus-selected burstsignals can be transmitted.

(10) Further, in order to solve the above-mentioned problem, accordingto the present invention, in a transmitting device in a mobilecommunication system in which a burst signal is transmitted to areceiving station at a transmission power value and/or transmission ratedetermined in accordance with a state of a radio channel between thetransmitting station and receiving station in a mobile communicationsystem, transmission permission criterion determining means whichdetermines a transmission permission criterion of the burst signal,determining means which determines as to whether or not the burst signalis to be transmitted based on a comparison result between thetransmission permission criterion determined by the transmissionpermission criterion detecting means and the state of the radio channelwith the receiving station, and transmission control means whichtransmits the burst signal to the receiving station when it has beendetermined by the determining means that the burst signal is to betransmitted, are provided.

(11) Further, in order to solve the above-mentioned problem, accordingto the present invention, in a method of distributing information to amobile set in a mobile communication system in which communication isperformed between a base station and the mobile set, one or a pluralityof base stations are determined to perform communication with the mobileset; information to be distributed to the mobile set is distributed tothe thus-determined one or plurality of base stations; and each basestation transmits the thus-distributed information to the mobile set.

In such an information distributing method in a mobile communicationsystem, information to be distributed to a mobile set is distributed toa plurality of base stations, and, from each base station, thethus-distributed information is transmitted to the mobile set. Asinformation to be distributed to a mobile set is distributed to aplurality of base stations, and, from each base station, thethus-distributed information is transmitted to the mobile set, it ispossible to adaptively alter a mode of distributing the information by amanner of distribution of the information to be distributed, such as thestate of the base stations to which the information to be distributed isdistributed, the state of the radio channels between the respective basestations to which the information is distributed and the mobile set,distributing amounts of the information, or the like.

The number of the base stations to perform communication with the mobileset may be fixedly predetermined based on the disposition of the basestations, expected communication traffic, and/or the like, or may bealtered appropriately based on required communication quality, requiredinformation transmission rate, states of the radio channels between therespective base stations and mobile set, and/or the like.

(12) In a standpoint that transmission of information from a basestation having a better state of a radio channel with the mobile set canbe made, according to the present invention, one or a plurality of basestations to perform communication with the mobile set may be determinedbased on a state of a radio channel with the mobile set.

The above-mentioned state of the radio channel represents a transmissionstate of radio wave (information) between the mobile set and basestation, directly or indirectly, and, may be expressed by, for example,any of or a combination of some of instantaneous pass loss variationvalue in the radio channel, data transmission error rate, transmissionthroughput, distance between the mobile set and base station, relativepositional relationship between the base station and mobile set,interference power value from another transmitting station which theradio channel receives, the number of mobile sets on the other ends towhich transmission is to be made through a same antenna, required time,transmission data amount, short-span average thereof, and long-spanaverage thereof.

(13) When information is distributed, various performances are requiredfor the information distribution. In a standpoint that the requirementsfor the information distribution can be properly dealt with, accordingto the present invention, in the above-mentioned informationdistributing method in a mobile communication system, one or a pluralityof base stations to perform communication with the mobile set may bedetermined based on performances required for transmission of theinformation to be distributed to the mobile set.

The performances required for transmitting the burst signal representperformances required when the burst signal is transmitted, and, forexample, may be expressed by any of or a combination of some of requiredtransmission rate, required transmission priority level, required errorrate, required maximum delay amount, and required average delay amount,and so forth.

(14) According to the present invention, in a standpoint thatinformation to be distributed can be properly distributed in accordancewith an amount of information piled up in each base station, one or aplurality of base stations to perform communication with the mobile setmay be determined based on a transmission waiting state of informationto be distributed in each base station.

The transmission waiting state for the information to be transmitted ineach base station represents a waiting state until the informationprovided to each base station is transmitted to the mobile set, directlyor indirectly, and, for example, may be expressed by any of or acombination of some of the data amount of the information in the waitingstate, the maximum delay time of the information in the waiting state,and the average delay time of the information in the waiting state.

(15) When a fixed amount of information is distributed to the mobileset, in a standpoint that an amount of information transmitted from eachbase station can be reduced, according to the present invention, theinformation to be distributed to the mobile set may be distributed tothe thus-determined plurality of base stations without duplication.

In such an information distributing method in a mobile communicationsystem, as the information to be distributed to the mobile set isdistributed to the thus-determined plurality of base stations withoutduplication, when information is distributed to the mobile set, theamount of information transmitted from each base station can be reducedthan an amount of the information in a case where the information istransmitted from a single base station. As a result, a transmission timeof information of each base station when the information is transmittedto the mobile set is shortened, and information transmission from eachbase station to the mobile set is not likely to be subject to variationin state of radio channel which may occur randomly.

(16) In a standpoint that information distribution can be made to themobile set more positively, according to the present invention, in theabove-mentioned information distributing method in a mobilecommunication system, a part or all of the information to be distributedto the mobile set may be copied, and the information to be distributedto the mobile set may be distributed to the thus-determined plurality ofbase stations with duplication of the part or all of the information.

In such an information distributing method in a mobile communicationsystem, as the information to be distributed to the mobile set isdistributed to the thus-determined plurality of base stations withduplication of the part or all of the information, when a quality ofinformation transmitted from any base station is degraded, thequality-degraded information can be made up with correspondinginformation transmitted from another base station duplicately. As aresult, it is possible to perform information distribution to the mobileset more positively.

(17) In a standpoint that communication traffic of each base station canbe equalized, according to the present invention, in the above-mentionedinformation distributing method in a mobile communication system, alarger amount of the information may be distributed to a base station ofthe thus-determined plurality of base stations which has a smalleramount of information in a transmission waiting state.

(18) In a standpoint that a larger amount of information can betransmitted to the mobile set through a better radio channel, a largeramount of the information may be distributed to a base station of thethus-determined plurality of base stations which has a better state ofthe radio channel with the mobile set.

The matter that the state of the radio channel is better means that thetransmission state of radio wave (information) between the mobile setand base station is more satisfactory, and, may be expressed by, forexample, respective states in that the instantaneous path loss variationvalue and/or short-span average thereof in the radio channel is smaller,the data transmission error rate is smaller, the transmission throughputis larger, the distance between the mobile set and base station isshorter, the interference power value from another transmitting stationreceived by the radio channel is smaller, the number of mobile sets onthe other ends to which transmission is to be made through a singleantenna is smaller, and/or the like.

(19) In a standpoint that information can be distributed to the mobileset in a more appropriate state in consideration of informationcommunication quality and information distribution time, according tothe present invention, in the above-mentioned information distributingmethod in a mobile communication system, amounts of distributing theinformation to the determined plurality of base stations may bedetermined based on an amount of information in a transmission waitingstate and a state of the radio channel with the mobile set in each basestation.

From the amount of information in the transmission waiting state in eachbase station, a distribution time of the information can be estimated,and, also, based on the state of the radio channel between each basestation and the mobile set, information communication quality can beestimated. Accordingly, when the amounts of distributing the informationto the respective base stations are determined based on the amount ofinformation in the transmission waiting state and the state of the radiochannel with the mobile set in each base station, it is possible toperform information distribution in a more appropriate state inconsideration of a combination of information communication quality andinformation distribution time.

(20) For example, the information may be distributed to thethus-determined plurality of base stations in a manner such that a basestation having a better state of the radio channel with the mobile setmay have a larger amount of information in a transmission waiting state.In this information distributing method in a mobile communicationsystem, it is possible to perform information distribution in a state ofbetter communication quality.

(21) In a standpoint that information distribution to the mobile set canbe performed more quickly, according to the present invention, in theinformation distributing method in a mobile communication system, when astate of information piled up in a transmission waiting state in eachbase station becomes a predetermined state, a part or all of theinformation in a transmission waiting state may be collected; and thethus-collected information may be re-distributed to one or a pluralityof base stations as information to be distributed.

By re-distributing the transmission waiting information which can beregarded as being not likely to be transmitted in each base station toanother base station, it is possible to distribute the information tothe mobile set more quickly.

The determination as to whether or not the transmission waitinginformation is not likely to be transmitted in each base station can bemade by time out, or whether or not a vacancy situation occurs inanother base station, or the like.

(22) Further, in a standpoint that a large amount of information can bedistributed to the mobile set without delay, according to the presentinvention, in the above-mentioned information distributing method in amobile communication system, when the above-mentioned information iscollected, if a time for which the thus-collected information has beenpiled up without being transmitted to the mobile set is longer than apredetermined time, this collected information may be discarded.

In such an information distributing method in a mobile communicationsystem, as information which has been piled up for a long time in eachbase station is discarded, it is possible to distribute informationwhich is provided sequentially to the mobile set without delay.

(23) Further, in order to solve the above-mentioned problem, accordingto the present invention, in an information distribution control deviceperforming information distribution control for a mobile set in a mobilecommunication system having a base station and the mobile set, basestation determining means determining one or a plurality of basestations to perform communication with the mobile set; and informationdistributing means distributing information to be distributed to themobile set to the thus-determined one or plurality of base stations areprovided, each base station being able to transmit the informationdistributed by the information distributing means to the mobile set.

(24) Further, the above-mentioned problem can be solved by atransmitting device in a mobile communication system in a receivingdevice in the mobile communication system which transmits a burst signaltransmitted from a transmitting station at a transmission power valueand/or a transmission rate determined in accordance with a state of aradio channel, comprising: reception quality measuring means measuring areception quality from a received signal; reception-end reference powerdetermining means determining a reception-end reference power inaccordance with the measured reception quality; a signal intensitydetector detecting the state of the radio channel; a reception-endpermission determining means determining whether or not the burst signalis to be transmitted by the transmitting station, based on a comparisonresult between the reception-end reference power and the state of theradio channel; and means transmitting this determination result to thetransmitting station. The measurement of the radio channel can be madenot only by the transmitting device but also by the receiving device.Based on communication quality measured by the receiving device, areception-end reference power is determined, and, by a comparison resultwith the state of the radio channel, it is determined as to whether ornot the burst signal is to be transmitted by the transmitting end, andit is sent to the transmitting end. Thereby, even the transmitting endcan perform transmission of the burst signal in consideration of thestate of the radio channel. Further, when also the transmitting enddetermines as to whether or not the burst signal is to be transmitted,and, also, takes into account the determination result of the receivingend, it is possible to perform transmission control of the burst signalwith a higher accuracy.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing a configuration example of a mobilecommunication system to which a method of and a device for transmittinga burst signal in embodiments of the present invention are applied;

FIG. 2 is a block diagram showing a first example of atransmission/reception system in the mobile communication system in thefirst embodiment of the present invention;

FIG. 3 is a block diagram showing a second example of atransmission/reception system in the mobile communication system in thefirst embodiment of the present invention;

FIG. 4 is a block diagram showing a third example of atransmission/reception system in the mobile communication system in thefirst embodiment of the present invention;

FIG. 5 is a block diagram showing a fourth example of atransmission/reception system in the mobile communication system in thefirst embodiment of the present invention;

FIG. 6 is a block diagram showing a fifth example of atransmission/reception system in the mobile communication system in thefirst embodiment of the present invention;

FIG. 7 is a block diagram showing a transmission/reception system in themobile communication system in a second embodiment of the presentinvention;

FIG. 8 is a flow chart showing operation of a transmission permissiondetermining unit shown in FIG. 7;

FIG. 9 is a block diagram showing a transmission/reception system in themobile communication system in a third embodiment of the presentinvention;

FIG. 10 is a flow chart showing operation of a transmission permissiondetermining unit shown in FIG. 9;

FIG. 11 shows one configuration example of a waiting row unit used inthe embodiments of the present invention;

FIG. 12 is a flow chart showing an algorithm of determining atransmission permission criterion also reflecting an immediatelypreceding reference transmission value in the embodiments of the presentinvention;

FIG. 13 is a block diagram showing one configuration example of areceiving device which transmits a reception-end transmissionpermission/non-permission determination to a transmitting device in theembodiments of the present invention;

FIG. 14 is a flow chart showing operation of the transmitting deviceused in the embodiments of the present invention;

FIG. 15 is a block diagram showing a basic configuration example of amobile communication system to which an information distributing methodand an information distribution control device in a fourth embodiment ofthe present invention are applied;

FIG. 16 is a block diagram showing configurations of a control station,base stations and a mobile set concerning downlink communication in themobile communication system shown in FIG. 15;

FIG. 17 shows a configuration example of each base station shown inFIGS. 15 and 16; and

FIG. 18 is flow charts showing operations of the control station shownin FIGS. 15 and 16.

BEST MODE FOR EMBODYING THE PRESENT INVENTION

Embodiments of the present invention will now be described based on thedrawings.

A mobile communication system to which a method of and a device fortransmitting a burst signal in the embodiments is configured, as shownin FIG. 1, for example.

In FIG. 1, to a mobile station 10 such as a portable telephone, a PHSterminal or the like, an information processing apparatus (PC) 20 suchas a computer is connected. Further, the mobile station 10 performsradio communication with a base station 30 which is set in a servicearea for the mobile communication. Similarly, another mobile station 40to which an information processing apparatus (PC) 50 is connectedperforms radio communication with another base station 60. Therespective base stations 30 and 60 are connected together through apredetermined network 80.

In this mobile communication system, when data to be transmitted to theother information processing apparatus 50 from the informationprocessing apparatus 20 is provided to the mobile station 10, forexample, the mobile station 10 converts the data into a form of packets,and transmits the data in the form of packets to the base station 30wirelessly. The base station 30 having received this burst signal sendseach packet to the network 80 for the base station 60 based on atransmission destination identifier included in the packet. Then, thebase station 60 having received each packet transmits the data formed ineach received packet to the mobile station 40 as a burst signal. Themobile station 40 having received this burst signal transmits eachpacket included in the burst signal to the information processingapparatus 50. The present invention can also be applied to a system inwhich, instead of the information processing apparatus 20 and 50, otherinformation generating/inputting points such as mouths and ears of humanbeings are used.

System of transmitting/receiving the burst signal between the mobilestation 10 and base station 30, and between the base station 60 andmobile station 40 in the above-mentioned mobile communication systemwill now be described in detail as a first embodiment of the presentinvention. A first example of this transmitting/receiving system isconfigured as shown in FIG. 2, for example.

In FIG. 2, transmission/reception of the burst signal is performedbetween a transmitting device 100 provided in a transmitting station end(mobile station 10 or base station 60 in the above-mentioned example)and a receiving device 200 provided in a receiving station end (basestation 30 or mobile station 40 in the above-mentioned example).

The transmitting device 100 has a waiting row unit 101 in which theprovided burst signal (for example, data in a form of packets) arestored one by one, a data taking unit 102 taking out data to betransmitted from the waiting row unit 101, and acoding/modulating/amplifying unit 103 performing coding, modulating andamplifying on the data to be transmitted taken by the data taking unit102. Further, the transmitting device 100 has a channel state measuringunit 104 measuring, based on a signal received from the othercommunication party through an antenna 110, the state of the radiochannel between the transmitting device 100 and receiving device 200,and a required transmission power estimating unit 105 estimating atransmission power value of the burst signal to be transmitted based onthe state of the radio channel thus measured by the channel statemeasuring unit 104.

The above-mentioned channel state measuring unit 104 outputs any one ora combination of some of an instantaneous variation value of path loss,a data transmission error rate, a transmission throughput, a distancebetween the transmitting and receiving devices, a relative positionalrelationship between the transmitting and receiving devices, aninterference power value from other radio stations, the number of otherradio stations to which signals are to be transmitted through theantenna 110, a time at which transmission is desired to be made, anamount of data to be transmitted, and a short-span average thereof and along-span average thereof, for example, as information representing thestate of radio channel between the transmitting device 100 and receivingdevice 200. When the channel state measuring unit 104 outputs theinstantaneous path loss variation value as the information representingthe state of the relevant radio channel, for example, the requiredtransmission power estimating unit 105 calculates a transmission powervalue such that a received power at the receiving device 200 may be adesired reception power value (fixed value), by multiplying thereciprocal of the above-mentioned instantaneous path loss variationvalue by the desired reception power value, for example. When theinstantaneous path loss variation value and interference powershort-span average value are output as the information representing thestate of the radio channel, the required transmission power estimatingunit 105 calculates a transmission power value such that the ratio ofthe reception power to the interference power may be a fixed value, bymultiplying the reciprocal of the instantaneous path loss variationvalue by the interference power value short-span average value and theratio of the desired reception power value to the interference powervalue, for example.

Thus, the required transmission power estimating unit 105 outputs alarger transmission power value, as the state of radio channelrepresented by the information obtained from the channel state measuringunit 104 is bad, but outputs a smaller transmission power value, as thestate of the radio channel is good.

The transmitting device 100 further has a transmission permissioncriterion determining unit 106 a and a transmission permissiondetermining unit 107. The transmission permission criterion determiningunit 106 a calculates a reference transmission power value which is usedas a transmission permission criterion based on the informationrepresenting the state of the radio channel from the channel statemeasuring unit 104. For example, the reference transmission power valueis calculated based on information representing an average state of theradio channel from the channel state measuring unit 104 (for example,information depending on the distance between the transmitting andreceiving devices, information expressed by a short-span average of theabove-mentioned respective information (for example, one obtained frommultiplying a short-span average value of the instantaneous path lossvariation value by a fixed value). The transmission permissiondetermining unit 107 compares the reference transmission power valuedetermined by the transmission permission criterion determining unit 106a with the transmission power value calculated by the above-mentionedrequired transmission power estimating unit 105, and, outputs a controlsignal of permission/non-permission of transmission of the burst signalbased on the comparison result. For example, the transmission powervalue calculated by the required transmission power estimating unit 105is larger than the reference transmission power value due to a causethat fading decreases or the like, the transmission permissiondetermining unit 107 outputs a control signal of non-permission oftransmission of the burst signal to the data taking unit 102. On theother hand, when the state of the radio channel is relatively good, and,thus, the transmission power value calculated by the requiredtransmission power estimating unit 105 is equal to or lower than thereference transmission power value, the transmission permissiondetermining unit 107 outputs a control signal of permission oftransmission to the data taking unit 102.

The data taking unit 102 performs control as to whether or nottransmitting the burst signal, based on the control signal from thetransmission permission determining unit 107. That is, while receivingthe control signal of permission of transmission of the burst signalfrom the transmission permission determining unit 107, the data takingunit 102 takes data from the waiting row unit 101, and sends the data tothe coding/modulating/amplifying unit 103. Thecoding/modulating/amplifying unit 103 performs coding and modifyingprocessing on the data, and, also, performs amplifying processingthereon so that the transmission power value calculated by the requiredtransmission power estimating unit 105 can be obtained thereby. Then,the data having undergone the respective processing is transmitted tothe receiving device 200 through the antenna 110. On the other hand,while receiving the control signal of non-permission of transmission ofthe burst signal from the transmission permission determining unit 107,the data taking unit 102 interrupts taking of data from the waiting rowunit 101. As a result, no burst signal is transmitted from thetransmitting device 100.

In the above-mentioned example, when the state of the radio channelbetween the transmitting device 100 and receiving device 200 becomesunsatisfactory due to influence of fading or the like, transmission ofthe burst signal from the transmitting device 100 to the receivingdevice 200 is delayed until the state of the radio channel is improved.As a result, it is possible to reduce the peak transmission power, andto control the power consumption in the transmitting device 100. Also,it is possible to reduce interference to other radio stations.

A second example of the transmitting/receiving system in the mobilecommunication system shown in FIG. 1 is configured as shown in FIG. 3,for example.

In FIG. 3, a transmitting device 100 in this transmitting/receivingsystem (including the transmitting device 100 and a receiving device200) includes, same as the above-described first example, a waiting rowunit 101, a data taking unit 102, a coding/modulating/amplifying unit103, a channel state measuring unit 104, a required transmission powerestimating unit 105 and a transmission permission determining unit 107.

In this second example a transmission permission criterion determiningunit 106 b calculates a reference transmission power value which is usedas a criterion for permission/non-permission of transmission of burstsignal, based on information representing the state of the radio channelfrom the channel state measuring unit 104 and a state of the burstsignal which is a waiting state of being stored in the waiting row unit101.

For example, the transmission permission criterion determining unit 106b calculates the reference transmission power value based on theinformation representing the state of the radio channel from the channelstate measuring unit 104 as described above, and, further, corrects theabove-mentioned reference transmission power value based on theinformation representing a transmission waiting state of the burstsignal stored in the waiting row unit 101 such as, for example, any ofor a combination of some of the number of stored packets, the averagedelay amount thereof, and the maximum delay amount thereof. For example,as the average delay amount of the burst signal, the maximum delayamount thereof, or the number of stored packets becomes larger, thereference transmission power value calculated as mentioned above is madelarger. As a result, even in the state of the radio channel in which thetransmission power value should be made slightly larger, the burstsignal comes to be made to be transmitted. Accordingly, the burst signalto be transmitted is prevented from being piled up in the waiting rowunit 101 for a long time.

A third example of the transmitting/receiving system in the mobilecommunication system shown in FIG. 1 is configured as shown in FIG. 4,for example.

In FIG. 4, a transmitting device 100 of this transmitting/receivingsystem (including the transmitting device 100 and a receiving device200) includes, the same as the above-described first and secondexamples, a waiting row unit 101, a data taking unit 102, acoding/modulating/amplifying unit 103, a channel state measuring unit104, a required transmission power estimating unit 105 and atransmission permission determining unit 107.

In this third example, a transmission permission criterion determiningunit 106 c calculates the reference transmission power value which isused as a criterion of permission/non-permission of transmission of theburst signal, based on the information representing the state of theradio channel from the channel state measuring unit 104, the state ofthe burst signal which is a waiting state of being stored in the waitingrow unit 101, and, also, media information provided from a motherapparatus which is a supply source of the burst signals to betransmitted. The media information is performance required intransmission of information, such as, for example, a required datatransmission rate, an average transmission power value, a transmissionpriority level, a required error rate, a required maximum delay amount,a required average delay amount and/or the like.

For example, multimedia information (including images, voices,characters and so forth) to be transmitted is provided to thetransmitting device 100 as the burst signal, for example, Then,information of the performance required in transmission of theinformation, such as, for example, a required data transmission rate, anaverage transmission power value, a transmission priority level, arequired error rate, a required maximum delay amount, a required averagedelay amount and/or the like is provided to the transmitting device 100as the media information together with the relevant multimediainformation. The transmission permission criterion determining unit 106c corrects the reference transmission power value calculated based onthe state of the radio channel as described above, for example, based onthe information representing the waiting state of the burst signalstored in the waiting row unit 101, and the media information. Forexample, when the required data transmission rate is large, when therequired priority level is high, when the required error rate is low,when the required maximum delay amount or required average delay amountis small, or the like, determination is made such that the referencetransmission power value becomes relatively larger. As a result, themultimedia information having such requirement can be transmitted, evenin a state of the radio channel in which the transmission power valueshould be increased somewhat. Thus, it is possible to performtransmission of the burst signal according to the requirement.

A fourth example of the transmitting/receiving system in the mobilecommunication system shown in FIG. 1 is configured as shown in FIG. 5,for example.

In FIG. 5, a transmitting device 100 of this transmitting/receivingsystem (including the transmitting device 100 and a receiving device200) includes, the same as the above-described first through thirdexamples, a waiting row unit 101, a data taking unit 102, acoding/modulating/amplifying unit 103, a channel state measuring unit104, a required transmission power estimating unit 105 and atransmission permission determining unit 107.

In this fourth example, a transmission permission criterion determiningunit 106 d calculates, same as in the above-described third example, thereference transmission power value which is used as a criterion ofpermission/non-permission of transmission of the burst signal, based onthe information representing the state of the radio channel from thechannel state measuring unit 104, the state of the burst signal which isa waiting state of being stored in the waiting row unit 101, and, also,media information provided from a mother apparatus which is a supplysource of the burst signals to be transmitted. Further, theabove-mentioned media information is provided to the requiredtransmission power estimating unit 105.

The required transmission power estimating unit 105 calculates thetransmission power value such that signal reception can be made with apredetermined quality in the receiving device 200, based on theinformation representing the state of the radio channel from the channelstate measuring unit 104. Further, it corrects the thus-calculatedtransmission power value based on the media information for theinformation to be transmitted.

For example, when the required data transmission rate is large, when therequired priority level is high, when the required error rate is low,when the required maximum delay amount or required average delay amountis small, or the like, the correction is made such that the transmissionpower value may be relatively larger. In this case, in consideration ofdependency of the transmission power value calculated by the requiredtransmission power estimating unit 105 on the media information, thetransmission permission criterion determining unit 106 d corrects thereference transmission power value based on the relevant mediainformation. That is, the relevant reference transmission power value isdetermined based on the relevant media information so as to preventactual transmission of the burst signal from being missed bydetermination as to whether or not transmission of the burst signal ispermitted made by the transmission permission determining unit 107 basedon comparison result between the transmission power value determineddepending on the media information as mentioned above and the referencetransmission power value calculated based on the relevant mediainformation

Thus, according to the fourth example, as the transmission power valueis determined according to requirement for transmission of informationto be transmitted, the power resource of the transmitting device 100 canbe distributed properly according to the requirement for the relevanttransmission of information to be transmitted.

A fifth example of the transmitting/receiving system in the mobilecommunication system shown in FIG. 1 is configured as shown in FIG. 6,for example.

In FIG. 6, a transmitting device 100 of this transmitting/receivingsystem (including the transmitting device 100 and a receiving device200) includes, the same as the above-described first through fourthexamples, a waiting row unit 101, a data taking unit 102, acoding/modulating/amplifying unit 103, a channel state measuring unit104, a required transmission power estimating unit 105 and atransmission permission determining unit 107. Further, the transmissionpermission criterion determining unit 106 e and required transmissionpower estimating unit 105 calculate the reference transmission powervalue and transmission power value, respectively, based on theabove-mentioned multimedia information, same as in the above-describedfourth example.

Further, in this fifth example, the transmission permission criteriondetermining unit 106 e reports any one of or a combination of some ofthe provided media information, the information representing the stateof waiting of transmission of the burst signal from the waiting row unit101 and the information representing the state of the radio channel fromthe channel state measuring unit 104, to a mother apparatus which is asupply source of the information to be transmitted. For example, in acase where the transmitting device 100 is mounted in the mobile station10 shown in FIG. 1, the current transmission error rate and/or length ofthe waiting row are reported to the information processing apparatus 20from the transmission permission criterion determining unit 106 e. Theinformation processing apparatus 20 having received such information canperform control such as to raise the transmission priority levelconcerning transmission of the information to be transmitted, lower thetransmission priority level concerning transmission of the otherinformation, or lower the communication quality so as to lower therequired data transmission rate. As a result, it is possible to transmitinformation for which various performances are required, whilesatisfying the requirements, without delay, and, also, in a condition inwhich the peak power is controlled as low as possible, from thetransmitting device 100 to the receiving device 200.

In each of the above-mentioned examples, the transmission permissiondetermining unit 107 performs determination of permission/non-permissionof transmission by a single reference value (reference transmissionpower value). However, a method of the determination is not limitedthereto. For example, a method in which a reference value for permittingtransmission and a reference value for inhibiting transmission areprepared individually, a method of performing determination ofpermission/non-permission of transmission by using a state transitiondiagram, or a method of performing determination ofpermission/non-permission of transmission by using a neural network, maybe employed. The criterion according to such a method of thedetermination performed by the transmission permission determining unit107 is provided to the transmission permission determining unit 107 fromthe transmission permission criterion determining unit 106 a (106 bthrough 106 e).

Further, in each of the above-mentioned examples, the transmissionpermission determining unit 107 employs the transmission power valuecalculated by the required transmission power estimating unit 105calculated based on the state of the radio channel, as the informationrepresenting the state of the radio channel. However it is not limitedthereto. Any of information representing the state of the radio channelobtained by the channel state measuring unit 104, or any informationobtained based on the above-mentioned information can be employed. Alsoin this case, the transmission power permission criterion determiningpart 106 a (106 b through 106 e) determines the criterion expressed byinformation which can be used in comparison with information provided asthe information representing the state of the radio channel.

With reference to FIG. 7, a mobile communication system to which amethod of and a device for transmitting the burst signal in a secondembodiment of the present invention will now be described.

In the above-described first embodiment, permission/non-permission oftransmission of the burst signal is determined based on the transmissionpower. In contrast thereto, according to the second embodiment,permission/non-permission of transmission of the burst signal isdetermined by referring to, in addition to the transmission power, anadaptive modulation transmission rate. The adaptive modulation is toalter a transmission rate (transmission speed) while the transmissionpower transmitted between the base station and mobile station is fixed.Thereby, when the state of the radio channel becomes worse, it ispossible to prevent the required transmission power from increasing, bylowering the transmission rate, according to the adaptive modulation. Atransmitting device 100 of a transmitting/receiving system (includingthe transmitting device 100 and a receiving device 200) shown in FIG. 7includes a waiting row unit 101, a data taking unit 102, acoding/modulating/amplifying unit 103, a channel state measuring unit104, a transmission power and transmission rate determining unit 105 aand a transmission permission determining unit 107 a.

FIG. 8 shows one example of an algorithm of the transmission permissiondetermining unit determining permission/non-permission of transmissionof the burst signal. The transmission permission determining unit 107 adetermines a reference transmission power value according to the stateof the radio channel measured by the channel state measuring unit 104and the media information, and, also, determines a referencetransmission rate value according to the above-mentioned state of theradio channel (a step S11). That is, the transmission permissiondetermining unit 107 a internally includes a transmission permissionreference determining unit determining the reference transmission powervalue and reference transmission rate. The above-mentioned processing ofdetermining permission/non-permission of transmission is such that, asdescribed above, based on the information representing the state of theradio channel from the channel state measuring unit 104 and the state ofthe burst signal which is a waiting state of being stored in the waitingrow unit 101, and, also, the media information provided by a motherapparatus which is a supply source of the burst signals to betransmitted, the reference transmission power value which is a criterionof permission/non-permission of transmission of the burst signal. Themedia information is performance required for transmission of theinformation such as the required data transmission rate, averagetransmission power value, transmission priority level, required errorrate, required maximum delay amount, required average delay amountand/or the like, for example.

Then, the transmission permission determining unit 107 a inputs thetransmission power value and the transmission rate determined accordingto the state of the radio channel and media information determined bythe transmission power and transmission rate determining unit 105 a (astep S12). Then, the transmission permission determining unit 107 adetermines whether or not the transmission power value is lower than thereference transmission power value and, also, the transmission rate ishigher than the reference transmission rate (a step S13). When thetransmission power value is lower than the reference transmission powervalue and, also, the transmission rate is higher than the referencetransmission rate, the transmission permission determining unit 107 aoutputs a control signal of permitting transmission of the burst signalto the data taking unit 102 (a step S14), and finishes the processing.Otherwise, the transmission permission determining unit 107 a outputs acontrol signal of not permitting transmission of the burst signal to thedata taking unit 102 (in a step S15), and finishes the processing.

Thus, according to the second embodiment of the present invention,permission of transmission of the burst signal is determined by usingboth the transmission power and transmission rate. Thereby, slightdegradation of state of the radio channel is dealt with by alteration ofthe transmission rate, and, then, the transmission is deferred when thechannel state is further degraded. Thereby, it is possible to furthereffectively reduce the required transmission power.

It is also possible to determine permission of transmission of the burstsignal by using only the transmission rate. In this case, the blocks 105a and 107 a shown in FIG. 7 process only the transmission rate, and, inthe steps S11, S12 and S13 shown in FIG. 8, only the transmission rateis processed.

The above-mentioned first and second embodiments relate to transmissionof the single burst signal. That is, the transmitting device 100transmits the burst signal to the single receiving device 200. Incontrast thereto, according to a third embodiment of the presentinvention which will now be described, permission of transmission of aplurality of burst signals is performed unitarily. That is, according tothe third embodiment, in a system in which the plurality of burstsignals have information indicating destinations(transmission-destination receiving devices), respectively, and, aretransmitted to the corresponding plurality of receiving devices,permission of the plurality of burst signals are managed unitarily.

FIG. 9 is a block diagram showing the third embodiment of the presentinvention. A transmitting device 100 of a transmitting/receiving system(including the transmitting device 100 and a receiving devices 200 ₁through 200 _(M)) shown in FIG. 9 includes a waiting row unit 101, adata taking unit 102, a coding/modulating/amplifying unit 103, a channelstate measuring unit 104, a transmission power and transmission ratedetermining unit 105 a and a transmission permission determining unit107 a. This block configuration itself is the same as that of thetransmitting device 100 shown in FIG. 7. However, the transmittingdevice 100 shown in FIG. 9 is different from the transmitting device 100shown in FIG. 7 in the following points:

The waiting row unit 101 can store N burst signals provided by a motherapparatus. That is, the waiting row unit 101 has N waiting rows. Thetransmitting device 100 can transmit, to the M receiving devices 200 ₁through 200 _(M), corresponding M burst signals. That is, the respectiveburst signals have information indicating destination numbers,respectively. The respective receiving devices 200 ₁ through 200 _(M)take therein transmitted bursts addressed thereto through antennas 210 ₁through 210 _(M), respectively.

In cellular mobile communication, in order to reduce interference powerto another cell, there is a case where an upper limit is provided to atotal of transmission power from one base station. In order to achieveit, the transmission permission determining unit 107 a determines a setof transmission permission bursts such that a total of transmissionpowers from the transmission antenna 110 does not exceed a predeterminedthreshold, with reference to transmission power of each burst signal.

One example of a method for this determination will now be described.

The burst signals are seen in a predetermined order, and, when the totalof the transmission powers after the media is added thereto does notexceed the threshold, transmission permission is given to the burstsignal. When it exceeds the threshold, transmission of the burst signalis made not permitted. This is performed on all the media. Thepredetermined order is determined based on any of or a combination ofsome of the waiting row, media information, from the channel statemeasuring unit 104, and transmission power and transmission ratedetermining unit 105 a. Examples of the predetermined order are shownbelow:

{circle around (1)} The order from the media having a smallertransmission power;

{circle around (2)} The order from the media having a largertransmission power;

{circle around (3)} The order from the media having a longer waitingrow;

{circle around (4)} Based on the media information, the order from themedia having a smaller delay requirement;

{circle around (5)} The order from the media having a smaller valueobtained from multiplying the value of transmission power with theshort-span average value of instantaneous path losses thereof;

{circle around (6)} The order from the media having a largertransmission rate; and

{circle around (7)} The order from the burst signal obtaining a moresatisfactory determination from receiving-end transmission permissiondetermination (which will be described later).

The example of the above-mentioned {circle around (2)} will now begiven. It is assumed that the number N of burst signals is 4,transmission powers thereof (assuming the burst signals 1, 2, 3 and 4)are 0.5, 5, 3, 6, respectively, and the threshold of a total oftransmission powers are 10. When they are seen in the order from alarger transmission power, the following result is obtained: First, theburst signal 4 (transmission power 6) having the largest transmissionpower is selected. As the total of the transmission powers is 6, it islower than the threshold 10. Accordingly, transmission of the burstsignal 4 is permitted. Then, the transmission power of the burst signal2 having the second largest transmission power 5 is added to thetransmission power 6. In this case, the total of the transmission powersis 11, and exceeds the threshold. Accordingly, transmission of the burstsignal 2 is not permitted. Then, the transmission power of the burstsignal 3 having the third largest transmission power is added to thetransmission power 6. In this case, the total of the transmission powersis 9, and is lower than the threshold. Accordingly, in addition to theburst signal 4, transmission of the burst signal 3 is newly permitted.Then, the transmission power 0.5 of the burst signal 1 having the fourthlargest transmission power is added to the transmission power 9 (totalof the transmission powers of the burst signals 4 and 3). In this case,the total of the transmission powers is 9.5, and is lower than thethreshold. Accordingly, in addition to the burst signals 4 and 3,transmission of the burst signal 1 is newly permitted.

Thus, permission of transmission of the burst signal is determined inconsideration of transmission of the burst signal to, not only thereceiving device which is a destination of this burst signal, but alsoanother receiving device, that is, a state of another radio channel(represented as transmission power or transmission rate). The total oftransmission powers may be a total of instantaneous transmission powervalues, or may be an average value of a total within a fixed timeinterval.

FIG. 10 is a diagram showing one example of algorithm of unitarilydetermining permission of transmission of a plurality of burst signalsin the transmission permission determining unit 107 a shown in FIG. 9.The transmission permission determining unit 107 a determines areference total transmission power value in accordance with the statesof respective radio channels (radio channels connecting between thetransmitting device 100 and receiving devices 200 ₁ through 200 _(M),respectively) measured by the channel state measuring unit 104 and themedia information, and, also, determines a reference transmission ratevalue based on the states of the respective radio channels (step S21).The reference transmission rate value is determined for each radiochannel (each burst signal). Further, the reference total power value isdetermined based on information representing the states of therespective radio channels from the channel state measuring unit 104 andthe state of the burst signals which is the waiting state of beingstored in the waiting row unit 110, and, also, the media informationprovided by a mother apparatus which is a supply source of the burstsignals to be transmitted, and is used as a criterion ofpermission/non-permission of transmission of the burst signal. The mediainformation is performance required for transmission of information suchas required data transmission rate, average transmission power value,transmission priority level, required error rate, required maximum delayamount, required average delay amount and/or the like, for example.

Then, the transmission permission determining unit 107 a inputstransmission power values (maximum transmission power values) andtransmission rates (lowest transmission rates) for respective N burstsignals determined by the transmission power and transmission ratedetermining unit 105 a according to the states of the respective radiochannels and the media information (step 522). Then, the transmissionpermission determining unit 107 a re-arranges the N burst signalsaccording to the predetermined order (step S23). Then, the transmissionpermission determining unit 107 a sets an initial value 0 into aparameter S indicating a total of transmission powers (step S24). Then,the transmission permission determining unit 107 a selects the top burstsignal of the thus-re-arranged burst signals, and starts execution of apermission/non-permission determining loop consisting of steps S26through S28 (step S25).

The transmission permission determining unit 107 a determines whether ornot the transmission rate value of the thus-selected burst signal islarger than the reference transmission rate value, and also, thetransmission power value obtained from adding the transmission power ofthe thus-selected burst signal to the parameter S (set to 0 initially)is lower than the reference total power value (step S26). When thedetermination result thereof is YES, the transmission power value of theselected burst signal is added to the parameter S, and thus, the valueof the parameter S is updated (step S27). Then, the transmissionpermission determining unit 107 a outputs a control signal of permittingtransmission of the burst signal to the data taking unit 102 (step S28),and finishes the execution of the permission/non-permission determiningloop for the selected burst signal (step S29). In contrast thereto, whenthe determination result of the step S26 is NO, the transmissionpermission determining unit 107 a outputs a control signal of notpermitting transmission of the burst signal to the data taking unit 102(step S30). Then, the next burst signal is selected, and thepermission/non-permission determining loop is executed therefor.

When the determination result of the step S26 is NO, thepermission/non-permission determination loop is finished (step S29).

Thus, transmission of all the burst signals determined as YES in thestep S26 are permitted, and, thus, the sum of the transmission powersthereof does not exceed the reference total power value. Accordingly, itis possible to reduce the interference power for other cells in thecellular mobile communication.

With reference to FIG. 11, the waiting row unit 101 used in the firstthrough third embodiments of the present invention will now bedescribed.

The waiting row unit 101 shown in FIG. 11 includes a time informationadding unit 111, a transmission waiting memory 112, a time differencecalculating unit 113, a current time generating unit 114, a maximumdelay time/average delay time calculating unit 115, and a delay maximumvalue/average value/n-% value calculating unit 116. The input burstsignal has current time information added thereto for each transmissionunit (for example, packet length) by the time information adding unit111, and, then, is stored in the transmission waiting memory 112. When ataking request signal comes from the data taking unit 102, onetransmission unit (which may be one arriving at the earliest time, ormay be the most important one in a case where difference in importanceof information exists within the single burst signal) of the burstsignal stored in the transmission memory 112 is selected, and is sent tothe transmission difference calculating unit 113. The transmissiondifference calculating unit 113 sends the input transmission unit to thedata taking unit 102, and, also, calculates a time difference valuebetween the time information added thereto and the current time. As thedifference value, delay maximum value/average/value/n-% value arecalculated by the delay maximum value/average value/n-% valuecalculating unit 116, and the information is sent to the transmissionpermission determining unit 107 a.

The transmission waiting memory 112 calculates the amount of burstsignals stored by itself, and sends it to the transmission permissiondetermining unit 107 a as transmission waiting burst signal amountinformation. Further, the transmission waiting memory 112 sends part orall of the time information added to the transmission units of the burstsignals stored therein to the maximum delay time/average delay timecalculating unit 115. The maximum delay time/average delay timecalculating unit 115 calculates the maximum value/average delay timethereof, and sends them to the transmission permission determining unit107 a.

When the waiting row unit 101 is configured by the minimumparts/components, it is possible to omit the parts/components having (*)in FIG. 11.

In the above-mentioned first through third embodiments of the presentinvention, it may be determined whether or not a transmission permissioncriterion determined as described above is proper through comparisonbetween a required communication quality and an actual communicationquality, and it may be updated periodically. Procedure of thisdetermination is shown in a flow chart of FIG. 12. The flow chart shownin the figure is one executed by the above-described transmissionpermission determining unit 107, 107 a, and, regardless of whether ornot data is transmitted, the transmission permission criterion isupdated in a fixed period. In the following description, description ismade as of processing by the transmission permission determining unit107 a in the third embodiment, by a reason.

First, the transmission permission determining unit 107 a determines thereference transmission power value and reference transmission rate valueas described above (step S71), and determines whether or not an updatingtime has come (step S72). When the determination result of the step S72is NO, the transmission permission determining unit 107 a finishes theprocessing. In contrast thereto, when the determination result of thestep S72 is YES, the latest channel state is input (step S73).Specifically, it may be one obtained from measuring, for a fixed timeinterval, one (for example, average delay time, average transmissionrate, or the like) of the channel state concerning the quality oftransmission of the burst signal by the channel state measuring unit104. Then, the transmission permission determining unit 107 a determineswhether or not the reference transmission power value and referencetransmission rate value are proper (step S74). In the step S74, theresult obtained from the measurement in the step S73 is compared with arequired channel state, and, in accordance therewith, the transmissionpermission criterion is altered by a predetermined span (steps S75 andS76). Thereby, the transmission permission reference is adaptivelyaltered, and, thus, a required quality can be obtained. For example, ina case of the burst signal for which the average delay time is ‘a’required by the media information, the average delay time is measuredfor a fixed time interval, and, it is determined whether or not theresult thereof falls within a value range which is a predetermined range(a1, a2) (a1 and a2 are predetermined constants, and, a1<a<a2). When theaverage delay time falls within this range, the reference transmissionvalue is not altered. When the average delay time is equal to or shorterthan a−s, it can be seen that occasions of permission of transmissionare given more than necessary times, and, thus, in order to make thiscriterion harder, the reference transmission power value is lowered orthe reference transmission rate value is increased, or both areperformed. When the average delay time is equal to or longer than a+s,the reference transmission power value is increased or the referencetransmission rate value is lowered, or both are performed. The alteringspan of the reference transmission value may be fixed, or may be changedin accordance with the deviation degree from the predetermined range.

Here, it is assumed that Tp denotes the reference transmission powervalue, Tr denotes the reference transmission rate value, Δp denotes anupdating span of the reference transmission power value, and Δr denotesan updating span of the reference transmission rate value. In a stepS74, when it is determined that the reference transmission power valueis too low and/or the reference transmission rate value is too high,Tp+Δp is set as Tp, and Tr−Δr is set as Tr. In contrast thereto, when itis determined that the reference transmission power value is too highand/or the reference transmission rate value is too low, Tp−Δp is set asTp, and Tr+Δr is set as Tr. When it is determined as proper in the stepS74, no alteration of the reference transmission value is performed.

In the above-mentioned first through third embodiments of the presentinvention, determination of permission of transmission is made by thetransmission end based on the channel state measured by the transmissionend. However, determination of permission of transmission is not limitedto that made based on the channel state measured by the transmissionend, but one observed by the reception end can be transmitted to thetransmission end as a control signal. When observation is made by thereception end, the measurement value may be transmitted to thetransmission end as it is in a form of real number or the like as acontrol signal, or, this may be used for determination by the receptionend by using a criterion provided there, and a reception-endtransmission permission/non-permission determination expressed by anumerical value in two or more finite levels may be obtained therefrom,and may be transmitted to the transmission end.

With reference FIG. 13, an example of a configuration of a receivingdevice in a case where the reception end transmissionpermission/non-permission determination is transmitted to thetransmission end will now be described.

FIG. 13 is a block diagram showing one example of configuration of theabove-described receiving device 200 in the transmitting/receivingsystem in the mobile communication system in the first through thirdembodiments of the present invention. In the figure, the receivingdevice 200 includes a channel separating/demodulating/decoding unit 221,a reception quality measuring unit 222, a reception-end reference powervalue determining unit 223, a signal intensity detecting unit 224, acontrol signal modulating/amplifying unit 225 and a burst signal outputterminal 226.

In order that the receiving device 200 measures the channel state, thetransmitting device 100 sends out an intensity detecting signal by atransmission power value already known in the receiving device 200. Asthis intensity detecting signal, any signal can be used which can bedetected by the signal intensity detecting unit 224 of the receivingdevice 200, and, also, for which the transmission power value is alreadyknown. For example, it may be a single one using a common channel whichis common for a plurality of receiving devices from one transmittingdevice, or, it may be one using particular channels to the respectivereceiving devices. By using the common channel, a single intensitydetecting signal can be used by all the receiving devices, and, thus,the power utilization efficiency can be improved. Further, it may betransmitted always regardless of whether or not the burst signal to betransmitted exists, or may be transmitted only when the burst signal tobe transmitted exists. By transmitting it only when the burst signal tobe transmitted exists, it is possible to avoid useless processing by thereceiving device and sending out of the control signals when no burstsignal to be transmitted exists. Further, the intensity detection signalmay be transmitted continuously, or may be transmitted discontinuously(periodically or non-periodically). By transmitting the intensitydetecting signal continuously, the reception end can estimate thechannel state at any time. Further, the intensity detecting signal maybe a special signal for intensity detection (pilot signal), or may alsobe used as the control signal and/or burst signal.

In the configuration shown in FIG. 13, the reception quality measuringunit 222 measures the channel state seen from processing process andprocessing result of the data channel reception signal in the channelseparating/demodulating/decoding unit 221. The reception-end referencepower determining unit 223 determines a reception-end reference powerbased on the measurement result and a past reference power. For example,an n % value (a value, lower than which n % of all of the received burstsignals fall) of delay times of the received burst signals areperiodically measured, and, when the measurement result is larger than apredetermined target delay time, the reception-end reference power maybe lowered by a fixed value from the preceding one. Otherwise, thereception end reference power may be raised by a fixed value from thepreceding one

Further, the signal intensity detecting unit 224 of the receiving device200 estimates the channel state, and the reception-end transmissionpermission determining unit 225 compares it with the reception-endreference power. The comparison result may be a difference therebetween,or may be one obtained from converting it into a corresponding numericalvalue in finite levels by a range to which it belongs. The controlsignal modulating/amplifying unit 226 transmits the comparison result tothe transmitting device through an antenna 210. The comparison resultmay be transmitted each time the reception-end transmission permissiondetermination is generated by the reception-end transmission permissiondetermining unit 225, or only when it changes from the precedingly sentcomparison result. For example, when the reception-end transmissionpermission determination is transmitted as binary information, bytransmitting this determination periodically, it is possible to send thecontrol signal having a high anti-transmission-error property.Alternatively, by sending the information only when the determination isinverted, it is possible to reduce the amount of control signal.

By utilizing this as a part of the criterion of transmission permissiondetermination by the transmission permission determining unit 107, 107 aof the transmitting device 100, it is possible to perform thetransmission permission determination also in consideration of thecriterion of the channel state determined by the receiving device.Alternatively, by using the reception-end transmission permissiondetermination expressed by binary numerical value, as it is, as thetransmission permission determination in the transmission permissiondetermining unit of the transmitting device, it is possible to make amanner equivalently as if transmission permission is determined in thereception end device.

FIG. 14 is a flow chart showing operation of the transmitting device 100used in the above-described second and third embodiments of the presentinvention. First, the transmission permission determining unit 107 adetermines whether or not any burst signal exists in the waiting rowunit 101 (step S31). When the determination result thereof is YES, thetransmission power and transmission rate determining unit 105 a takesdata concerning the channel state and the media information from thechannel state measuring unit 104 (step S32), and determines thetransmission power and transmission rate in the manner described in thestep S12 of FIG. 8 or the step S22 of FIG. 10. Then, the transmissionpermission determining unit 107 a determines permission/non-permissionof transmission in accordance with the algorithm shown in FIG. 8 or FIG.10 (step S34). The transmission permission determining unit 107 acontrols the data taking unit 102, takes the burst signal for whichtransmission is permitted from the waiting row unit 101, and gives it tothe coding/modulating/amplifying unit 103 (step S35). Thecoding/modulating/amplifying unit 103 performs coding, modulating andamplifying of the burst signal for which transmission is permitted (stepS36), and transmits the burst signal through the antenna 110 (step S37).

The flow chart shown in FIG. 14 also shows transmission operation of thetransmitting device 100 used in the first embodiment of the presentinvention. However, in the first embodiment, only the transmission poweris used, and the transmission rate is not used.

The above-mentioned first through third embodiments of the presentinvention may be applied to control of information distribution. Oneexample of mobile communication system to which a method of informationdistribution to a mobile set and an information distribution controldevice are applied will now be described as a fourth embodiment of thepresent invention.

FIG. 15 is a block diagram showing the fourth embodiment of the presentinvention. In FIG. 15, to a mobile set (MS) 10 such as a portabletelephone, a PHS terminal or the like, an information processingapparatus (PC) 20 such as a computer is connected . Further, the mobileset 10 can perform radio communication with base stations 100 ₁, 100 ₂,. . . , 100 _(n) set in a service area of the mobile communication. Therespective base stations 100 ₁, 100 ₂, . . . , 100 _(n) are connected toa control station 40. The control station 40 controls the respectivebase stations (BS) 100 ₁, 100 ₂, . . . 100 _(n), and, also, performsrepeating of communication between respective base stations performingcommunication with the mobile set 10 and a network 50.

In particular, in downlink communication, the control station 40transmits data addressed to the mobile set 10 from the network 50 bydistributing it to base stations determined in accordance with a methoddescribed later. Further, this control station 40 monitors the basestations 100 ₁, 100 ₂, . . . , 100 _(n), collects data which isdetermined not to be transmitted from the respective base stations for awhile, and distributes it to other base stations again.

In the above-mentioned mobile station, the control station 40 andrespective base stations 100 ₁, 100 ₂, . . . , 100 _(n) are configuredas shown in FIG. 16, for example.

The configuration of operation of the control station 40 will now bedescribed with reference to FIG. 16 and a flow chart of FIG. 18.

The control station 40 has a time adding unit 41, a data transmittingbase station determining unit 42, a data distributing unit 43, anot-yet-transmitted data collecting unit 44, and a data discarddetermining unit 45. A basic control sequence of the control station 40is as shown in FIG. 18(A). The control station 40 determines whether ornot data to be distributed exists (step S41). When determining that itexists, the control station 40 distributes the data as shown in FIG.18(B) (step S42), and, then, performs a step S43. In the step S41, whendetermining that it does not exist, the control station 40 directlyproceeds to the step S43. In the step S43, when determining that data tobe collected exists, the control station 40 collects thenot-yet-transmitted data as shown in FIG. 18(C) (step S44), and finishesthe processing. In the step S43, when determining that no data to becollected exists, the control station 40 finishes the processing.

Each component of the control station 40 will now be described indetail.

The time adding unit 41 adds a reception time (time stamp) to data(packet) addressed to the mobile set 10 provided from the network 50(step S51). The data transmission base station determining unit 42determines base stations to which the data is transmitted for the mobileset 10, according to a method (step S52) described later. The datadistributor 43 distributes the data, to which the reception time isadded as mentioned above, to the base stations determined by the datatransmission base station determining unit 42 (step S54).

In this system, as data can be transmitted to the mobile set 10 from theplurality of base stations, the amount of data per unit time periodprovided to the control station 40 through the network 50 may exceed thedata amount per unit time period which can be transmitted by each basestation. Further, the unit data length (unit number of packets)distributed as mentioned above may be the same as the unit data lengthof data provided from the network 50, or may be different therefrom.

The not-yet-transmitted data collecting unit 44 collects packets whichare stored in the waiting row unit 120 of each base station withoutbeing transmitted for a fixed time interval, as packets which are notlikely to be transmitted (step S61). Further, it may collect packetswhen another base station has vacancy (waiting row becomes vacant), ormay collect packets in consideration of both the above-mentioned timeinterval and the vacancy states of other base stations. For the packetscollected by this not-yet-transmitted data collecting unit 4,determination is made as to whether or not they are to be discarded(step S62). This determination is performed based on a piled-up timecalculated based on the reception time added to each packet and thecurrent time. That is, when the piled-up time is equal to or longer thana predetermined time, the relevant packet is discarded (step S64). Thepackets not discarded are returned to the data distributor 43, and, aredistributed to respective base stations determined by the datatransmission base station determining unit 42 at this time (step S63).

Each transmitting station 100 ₁, 100 ₂, . . . , 100 _(n) is configuredby the transmitting device 100 of the above-described first throughthird embodiments. In FIG. 16, for the sake of convenience, only thewaiting row unit 101 and channel state measuring unit 150 of theabove-described components are shown, and the other components areindicated as a transmitter 121. That is, when each transmitting stab 100₁, 100 ₂, . . . , 100 _(n) has the configuration shown in FIG. 6, thetransmitter 121 of each base station includes, as shown in FIG. 17, thedata taking unit 102, coding/modulating/amplifying unit 103, requiredtransmission power estimating unit 105, transmission permissioncriterion determining unit 106 e and transmission permission determiningunit 107 described with reference FIG. 6. Further, when eachtransmitting stab 100 ₁, 100 ₂, . . . , 100 _(n) has the configurationshown in FIG. 7, the transmitter 121 of each base station includes thedata taking unit 102, coding/modulating/amplifying unit 103, requiredtransmission power and transmission rate determining unit 105 a andtransmission permission determining unit 107 a shown in FIG. 7.

The waiting row unit 101 stores therein data transmitted from thecontrol station 40 for packet units sequentially. The transmittingdevice 100 takes the data stored in the waiting row unit 101 intransmission timing, and transmits the data to the mobile set 10 throughthe antenna 110 wirelessly.

The above-mentioned channel state measuring unit 104 measures the stateof the radio channel between the transmitter 121 and the receivingdevice 200 of the mobile set 10. As information representing the stateof the radio channel, as described above, for example, any of or acombination of some of instantaneous path loss value between thetransmitting and receiving units, data transmission error rate,transmission throughput, distance between the transmitting and receivingunits, relative positional relationship between the transmitting andreceiving units, interference power value which the receiving device 200receives from transmitting wave from another transmitting station, thenumber of other mobile sets to which data is to be transmitted throughthe antenna 110, required time, data amount, short-span average value,long-span average value thereof, may be used.

The channel information representing the state of the radio channelmeasured by the channel state measuring unit 104 is provided to thetransmitter 121, and, also, is transmitted to the above-mentioned datatransmission base station determining unit 42 of the control station 40.The transmitter 121, when having the above-described configurationaccording to the first embodiment, determines the transmission power andtransmission timing based on this channel information, and, transmitsdata taken from the waiting row unit 101 in this transmission timing bythe determined transmission power.

The data to be transmitted wirelessly from each base station asmentioned above is received by the receiving device 200 in the mobileset 10 through the antenna 210. The thus-received data is furthertransmitted to the information processing apparatus 20, which thenprocesses the data.

The above-mentioned control station 40 distributes data addressed to themobile set 10 provided from the network 50 to respective base stations,by the following manner:

The data transmission station determining unit 42 determines basestations which are to transmit the data provided addressed to the mobileset 10, to the mobile set 10, based on the media information providedfrom the network together with the data, the above-mentioned channelinformation provided from the respective base stations 100 ₁, 100 ₂, . .. , 100 _(n), and, also, information indicating the data transmissionwaiting states (waiting row information) in the respective waiting rowunits 101 provided by the respective base stations 100 ₁, 100 ₂, . . . ,100 _(n).

The above-mentioned channel information indicates a degree by which thestate of the radio channel between each base station and mobile set 10is suitable for radio communication (small path loss, small error rate,small interference, small attenuation, and/or the like). Based on thechannel information, the data transmission determining unit 42 canselect base stations having the states of the radio channels with themobile set 10 which are those more suitable for radio communication.

Further, as the waiting row information, for example, any of or acombination of some of the number of packets of data stored in thewaiting row unit 101, the maximum delay time thereof and the averagedelay time thereof is used. Based on the waiting row information, it ispossible to determine a generous transmission waiting time of thedistributed data.

The media information provided to the data transmission base stationdetermining unit 42 as mentioned above is information indicatingperformance required for transmission of the data provided, and, forexample, is configured by any of or a combination of some of therequired data transfer rate, transfer priority level, required errorrate, required maximum delay amount, required average delay amount, andtransmission permission base station information (for eachcommunication, a group of base stations (for example, three stations)which are permitted to perform transmission).

The above-mentioned data transmission base station determining unit 42determines one or a plurality of base stations which can perform datatransmission to the mobile set 10 in a condition in which theperformance indicated by the media information is satisfied as possible,in consideration of combination of the above-mentioned channelinformation, waiting row information and media information. An algorithmof determining these base stations may be determined freely. Forexample, for each base station, the channel information, waiting rowinformation and media information are expressed by a numerical value,and, thus, a degree of suitability as a transmission base station iscalculated. Then, a predetermined number of the most superior basestations (3 base stations) are determined as base stations which performcommunication with the mobile set.

As a result of the base stations being thus determined based on thedegree of suitability, a base station which has a shorter waiting timein the waiting row unit 101 is given priority to be selected when datawhich should be transmitted to the mobile set 10 urgently (when therequired data transfer rate is large) is provided, for example. Further,when data which should be transmitted to the mobile set with greatimportance to quality provided (when the required error rate is small),a base station having a satisfactory state of the radio channel with themobile set 10 is given priority to be selected as the transmission basestation.

After the plurality of base stations to transmit the data to the mobileset 10 are determined by the data transmission base station determiningunit 42 as mentioned above, the data distributor 43 distributes andtransmits the provided data to the determined plurality of basestations.

The algorithm of determining the base stations to which the data is tobe distributed can be determined freely.

For example, when priority is given to positive transmission of data tothe mobile set 10, part or all of the data to be transmitted can becopied, and thus, the part or all of the data can be distributed to theplurality of base stations with duplication. Further, when priority isgiven to soonest possible transmission of data to the mobile set 10, thedata to be transmitted is divided, and the divided data can bedistributed to the respective base stations without duplication.

Distribution amounts to the respective base stations in the distributionof data performed by the data distributor 43 may be equal distribution,or may be distribution with a fixed rate in the order of the degree ofsuitability calculated for each base station determined as mentionedabove. Further, the distribution amounts of data to the respective basestations may be determined based on any of or a combination of some ofthe waiting row information and channel information provided from theabove-mentioned respective base stations. For example, it is possible todetermine the distribution amounts of data in a manner such that alarger amount of data may be stored in the waiting row unit 101 of abase station having a better state of the radio channel with the mobileset 10.

Each base station having received the data distributed as mentionedabove transmits the data to the mobile set 10 to which the data isaddressed. In a process of transmission (distribution) of the data tothe mobile set 10 from each base station, the not-yet-transmitted datacollecting unit 44 inspects waiting data (packets) in the waiting rowunit 101 of each base station, and collects data which has been piled upfor a predetermined time or longer. Further, when vacancy occurs inanother base station, the not-yet-transmitted data collecting unit 44may collect data therefrom, or may collect data in consideration of boththe above-mentioned time and the vacancy state of another base station.Then, the collected packets undergo determination as to whether or notthey are discarded by the data discard determining unit 45. The packetsnot determined to be discarded are distributed again by the datadistributor 43 to one or a plurality of base stations determined by thedata transmission base station determining unit 42 at the time.

On the other hand, the packets which have the piled up times, eachobtained from the reception time and current time, equal to or longerthan the predetermined time are discarded in viewpoint that transmissionof other data without delay should be given priority.

As described above, according to the fourth embodiment of the presentinvention, base stations which perform communication with the mobile setare determined, and, also, distribution amounts of data to thethus-determined base stations are determined, based on any of or acombination of some of the waiting row information, channel informationand media information. Further, each base station, based on any of or acombination of some of the above-mentioned waiting row, channelinformation and media information, the transmission timing iscontrolled. Thereby, when information is distributed to the mobile set,the mobile set can receive the distributed information in a moresatisfactory state.

As described above, according to the present invention, transmissiontime (whether or not the burst signal is to be transmitted) of the burstsignal is determined in consideration of the state of the radio channel.Thereby, when the burst signal is transmitted, the time of transmissioncan be determined in a manner such that either one or both thetransmission power and transmission rate determined in accordance withthe state of the radio channel are not inappropriate for the mobilecommunication system as possible.

Further, according to the present invention, information to bedistributed to the mobile set is distributed to a plurality of basestations, and, from each of the plurality of base stations, thedistributed information is transmitted to the mobile set. Thereby, it ispossible to adaptively alter a mode of distributing the informationthrough a manner of distribution of the information to be distributedsuch as the states of the base stations to which the information to bedistributed is distributed, the states of the radio channels between therespective base stations to which the information is distributed and themobile set, distribution amounts of the information and so forth. As aresult, even when the base stations which perform communication with themobile set are determined in a relatively long period, (for example, theperiod of measuring of the channel is elongated), informationdistribution in a more appropriate mode can be performed through amanner of distributing the information. Accordingly, it is possible todistribute information to the mobile set in a manner such that receptionof the information by the mobile set can be performed in a state assatisfactory as possible while a control amount needed for theinformation distribution can be reduced as possible.

1. A method of transmitting a burst signal when the burst signal istransmitted from a transmitting station to a receiving station at atransmission power value and/or transmission rate determined inaccordance with a state of a radio channel between said transmittingstation and receiving station in a mobile communication system, wherein:it is determined as to whether or not the burst signal is to betransmitted based on a comparison result between a criterion previouslydetermined in accordance with the state of the radio channel and atransmission waiting state of said signal, and the state of the radiochannel between the transmitting station and receiving station; theburst signal is transmitted from the transmitting station to thereceiving station when it has been determined that the burst signal isto be transmitted; determining that a signal transmission permissioncriterion is made based on a channel state; and making a modification ofthe signal transmission permission criterion according to a transmissionwaiting state, in such a manner that the transmission permissioncriterion is made easier as the transmission waiting time is longer,while the transmission permission criterion is made more difficult asthe transmission waiting time is shorter.
 2. The method of transmittinga burst signal as claimed in claim 1, wherein: said criterion isdetermined based on the state of the radio channel.
 3. The method oftransmitting a burst signal as claimed in claim 1, wherein: thedetermination as to whether or not the burst signal is to be transmittedis performed further depending on performance required for transmittingthe burst signal.
 4. The method of transmitting a burst signal asclaimed in claim 3, wherein: said criterion is determined depending onthe performance required for transmitting the burst signal.
 5. Themethod of transmitting a burst signal as claimed in claim 3, wherein: atleast one of the transmission power value and transmission rate of theburst signal to be transmitted is determined further depending on theperformance required for transmitting the burst signal.
 6. The method oftransmitting a burst signal as claimed in claim 1, wherein: saidcriterion is expressed as a reference transmission power value andlorreference transmission rate, and, it is determined as to whether or notthe burst signal is to be transmitted based on the comparison resultbetween the reference transmission power value and/or referencetransmission rate and transmission power value and/or transmission ratedetermined in accordance with the state of the radio channel.
 7. Themethod of transmitting a burst signal as claimed in claim 1, wherein thestate of the radio channel comprises not only the state of the radiochannel between the transmitting station and receiving station to whichthe burst signal is addressed but also the state of a radio channel withanother receiving station.
 8. The method of transmitting a burst signalas claimed in claim 7, wherein said criterion is a reference total powervalue, and bursts which can be transmitted are selected from a pluralityof burst signals in a manner such that a total of transmission powervalues of the plurality of burst signals does not exceed the referencetotal power value.
 9. The method of transmitting a burst signal asclaimed in claim 8, wherein burst signals are selected from theplurality of burst signals in a predetermined order, and a total oftransmission power values is obtained, and, then, when said total doesnot exceed the reference total power value, it is determined that thethus-selected burst signals can be transmitted.
 10. A transmittingdevice in a mobile communication system in which a burst signal istransmitted to a receiving station at a transmission power value and/ortransmission rate determined in accordance with a state of a radiochannel with the receiving station, comprising: transmission permissioncriterion determining means determining a transmission permissioncriterion of the burst signal; determining means determining as towhether or not the burst signal is to be transmitted based on acomparison result between the transmission permission criteriondetermined by said transmission permission criterion detecting means, atransmission waiting state of the burst signal and the state of theradio channel with the receiving station; transmission control meanstransmitting the burst signal to the receiving station when it has beendetermined by said determining means that the burst signal is to betransmitted; determination means for determining a signal transmissionpermission criterion is made based on a channel state; and modificationmeans for making modification of the signal transmission permissioncriterion according to a transmission waiting state, in such a mannerthat the transmission permission criterion is made easier as thetransmission waiting time is longer, while the transmission permissioncriterion is made more difficult as the transmission waiting time isshorter.
 11. The transmitting device in a mobile communication system asclaimed in claim 10, wherein: said transmission permission criteriondetermining means determines the transmission permission criterion basedon the state of the radio channel with the receiving station.
 12. Thetransmitting device in a mobile communication system as claimed in claim10, wherein: said transmission permission criterion determining meansdetermines the transmitting permission criterion further depending onthe transmission waiting state of the burst signal.
 13. The transmittingdevice in a mobile communication system as claimed in claim 10, wherein:a determination result by said determining means further depends onperformance required for transmitting the burst signal.
 14. Thetransmitting device in a mobile communication system as claimed in claim13, wherein: said transmission permission criterion determining meansdetermines the transmission permission criterion further depending onthe performance required for transmitting the burst signal.
 15. Thetransmitting device in a mobile communication system as claimed in claim13, comprising: transmission power determining means determines thetransmission power value of the burst signal to be transmitted based onthe performance required for transmitting the burst signal as well asthe state of the radio channel.
 16. The transmitting device in a mobilecommunication system as claimed in claim 15, wherein: said transmissionpermission criterion determining means determines a referencetransmission power value as the transmission permission criterion; andsaid determining means determines as to whether or not the burst signalis to be transmitted based on the comparison result between thereference transmission power value determined by said transmissionpermission criterion determining means and the transmission power valuedetermined in accordance with the state of the radio channel.
 17. Thetransmitting device in a mobile communication system as claimed in claim13, comprising a transmission rate determining means determining thetransmission rate of the burst signal to be transmitted based on theperformance required for transmitting the burst signal as well as thestate of the radio channel.
 18. The transmitting device in a mobilecommunication system as claimed in claim 10, wherein: said transmissionpermission criterion determining means determines a referencetransmission rate; and said determining means determines as to whetheror not the burst signal is to be transmitted based on the comparisonresult between the reference transmission rate value determined by saidtransmission permission criterion determining means and the transmissionrate value determined in accordance with the state of the radio channel.19. The transmitting device in a mobile communication system as claimedin claim 10, wherein: said transmission permission criterion determiningmeans determines a reference transmission power value and a referencetransmission rate; and said determining means determines as to whetheror not the burst signal is to be transmitted based on the comparisonresult between the reference transmitting power value and referencetransmission rate value determined by said transmission permissioncriterion determining means and the transmission power value andtransmission rate value determined in accordance with the state of theradio channel.
 20. The transmitting device in a mobile communicationsystem as claimed in claim 10, wherein said detennining means makes thedetermination in consideration of not only the state of the radiochannel between the transmitting station and receiving station to whichthe burst signal is addressed but also the state of a radio channel withanother receiving station.
 21. The transmitting system in a mobilecommunication system as claimed in claim 20, wherein: said transmissionpermission criterion determining means determines a reference totalpower value as the transmission permission criterion; and saiddetermining means selects bursts which can be transmitted from aplurality of burst signals in a maimer such that a total of transmissionpower values of the plurality of burst signals does not exceed thereference total power value.
 22. The transmitting system in a mobilecommunication system as claimed in claim 21, wherein: said determiningmeans selects burst signals from the plurality of burst signals in apredetermined order, and a total of transmission power values isobtained, and, then, when said total does not exceed the reference totalpower value, said determining means determines that the thus-selectedburst signals can be transmitted.
 23. A method of distributinginformation to a mobile set in a mobile communication system in whichcommunication is performed between a base station and the mobile set,wherein: one or a plurality of base stations are determined to performcommunication with the mobile set, and based on a transmission waitingstate of information to be distributed in each base station; informationto be distributed to the mobile set is distributed to thethus-determined one or plurality of base stations; each base stationtransmits the thus-distributed information to the mobile set;determining that a signal transmission permission criterion is madebased on a channel state; and making a modification of the signaltransmission permission criterion according to a transmission waitingstate, in such a manner that the transmission permission criterion ismade easier as the transmission waiting time is longer, while thetransmission permission criterion is made more difficult as thetransmission waiting time is shorter.
 24. The method of distributinginformation in a mobile communication system as claimed in claim 23,wherein: the one or plurality of base stations to perform communicationwith the mobile set are determined based on a state of a radio channelwith the mobile set.
 25. The method of distributing information in amobile communication system as claimed in claim 23, wherein: the one orplurality of base stations to perform communication with the mobile setare determined based on performance required for transmission of theinformation to be distributed to the mobile set.
 26. The method ofdistributing information in a mobile communication system as claimed inclaim 23, wherein: the information to be distributed to the mobile setis distributed to the thus-determined one or plurality of base stationswithout duplication.
 27. The method of distributing information in amobile communication system as claimed in claim 23, wherein: a part orall of the information to be distributed to the mobile set is copied,and the information to be distributed to the mobile set is distributedto the thus-determined one or plurality of base stations withduplication of the part or all of the information.
 28. The method ofdistributing information in a mobile communication system as claimed inclaim 23, wherein: a larger amount of the information is distributed toa base station of the thus-determined one or plurality of base stationswhich has a smaller amount of information in a transmission waitingstate.
 29. The method of distributing information in a mobilecommunication system as claimed in claim 23, wherein: a larger amount ofthe information is distributed to a base station of the thus-determinedone or plurality of base stations which has a better state of the radiochannel with the mobile set.
 30. The method of distributing informationin a mobile communication system as claimed in claim 23, wherein:amounts of distributing of the information to the thus-determined one orplurality of base stations are determined based on an amount ofinformation in a transmission waiting state and a state of the radiochannel with the mobile set in each base station.
 31. The method ofdistributing information in a mobile communication system as claimed inclaim 30, wherein: the information is distributed to the thus-determinedone or plurality of base stations in a manner such that a base stationhaving a better state of the radio channel with the mobile set may havea larger amount of information in a transmission waiting state.
 32. Themethod of distributing information in a mobile communication system asclaimed in claim 23, wherein: when a state of information piled up in atransmission waiting state in each base station becomes a predeterminedstate, a part or all of the information in a transmission waiting stateis collected; and the thus-collected information is re-distributed toone or a plurality of base stations as information to be distributed.33. The method of distributing information in a mobile communicationsystem as claimed in claim 32, wherein: the collected information isdiscarded if a time for which the information is piled up without beingtransmitted to the mobile set is more than a predetermined time when theinformation is collected.
 34. An information distribution control deviceperforming information distribution control for a mobile set in a mobilecommunication system having a base station and the mobile set,comprising: base station determining means determining one or aplurality of base stations to perform communication with the mobile setand based on a transmission waiting state of the information to bedistributed in each base station; and information distributing meansdistributing information to be distributed to the mobile set to thethus-determined one or plurality of base stations, each base stationbeing able to transmit the information distributed by said informationdistributing means to the mobile set; determination means fordetermining a signal transmission permission criterion is made based ona channel state; and modification means for making modification of thesignal transmission permission criterion according to a transmissionwaiting state, in such a manner that the transmission permissioncriterion is made easier as the transmission waiting time is longer,while the transmission permission criterion is made more difficult asthe transmission waiting time is shorter.
 35. The informationdistributing control device as claimed in claim 34, wherein: said basestation determining means determines the one or plurality of basestations to perform communication with the mobile set based on a stateof a radio channel with the mobile set.
 36. The information distributingcontrol device as claimed in claim 34, wherein: said base stationdetermining means determines the one or plurality of base stations toperform communication with the mobile set based on performance requiredfor transmission of the information to be distributed to the mobile set.37. The information distributing control device as claimed in claim 34,wherein: said information distributing means distributes the informationto be distributed to the mobile set to the thus-determined one orplurality of base stations without duplication.
 38. The informationdistributing control device as claimed in claim 34, wherein: saidinformation distributing means copies a part or all of the informationto be distributed to the mobile set, and distributes the information tobe distributed to the mobile set to the thus-determined one or pluralityof base stations with duplication of the part or all of the information.39. The information distributing control device as claimed in claim 34,wherein: said information distributing means distributes a larger amountof the information to a base station of the thus-determined one orplurality of base stations which has a smaller amount of information ina transmission waiting state.
 40. The information distributing controldevice as claimed in claim 34, wherein: said information distributingmeans distributes a larger amount of the information to a base stationof the thus-determined one or plurality of base stations which has abetter state of the radio channel with the mobile set.
 41. Theinformation distributing control device as claimed in claim 34, wherein:said information distributing means determines amounts of distributingof the information to the thus-determined one or plurality of basestations based on an amount of information in a transmission waitingstate and a state of the radio channel with the mobile set in each basestation.
 42. The information distributing control device as claimed inclaim 41, wherein: said information distributing means distributes theinformation to the thus-determined one or plurality of base stations ina manner such that a base station having a better state of the radiochannel with the mobile set has a larger amount of information in atransmission waiting state.
 43. The information distributing controldevice as claimed in claim 34, further comprising information collectingmeans which, when a state of information piled up in a transmissionwaiting state in each base station becomes a predetermined state,collects a part or all of the information in the transmission waitingstate, said information distributing means re-distributing thethus-collected information to one or a plurality of base stations asinformation to be distributed.
 44. The information distributing controldevice as claimed in claim 43, further comprising: informationdiscarding means discarding the collected information if a time forwhich the information is piled up without being transmitted to themobile set is more than a predetermined time when the information iscollected.
 45. A transmitting device in a receiving device in a mobilecommunication system which transmits a burst signal transmitted from atransmitting station at a transmission power value and/or a transmissionrate determined in accordance with a state of a radio channel,comprising: reception quality measuring means measuring a receptionquality from a received signal; reception-end reference powerdetermining means determining a reception-end reference power inaccordance with the measured reception quality; a signal intensitydetector detecting the state of the radio channel; reception-endpermission determining means determining whether or not the transmittingstation should transmit the burst signal, based on a transmissionwaiting state of burst signal and a comparison result between thereception-end reference power and the state of the radio channel; meanstransmitting this determination result to the transmitting station;determination means for determining a sianal transmission permissioncriterion is made based on a channel state; and modification means formaking modification of the signal transmission permission criterionaccording to a transmission waiting state, in such a manner that thetransmission permission criterion is made easier as the transmissionwaiting time is longer, while the transmission permission criterion ismade more difficult as the transmission waiting time is shorter.